Frengen J, Schmid R, Kierulf B, Nustad K, Paus E, Berge A, Lindmo T
Department of Physics, University of Trondheim, Norway.
Clin Chem. 1993 Oct;39(10):2174-81.
We evaluated two homogeneous immunofluorometric assays (IFMAs) of alpha-fetoprotein (AFP) based on new macroporous acrylate particles combined with flow cytometry. The standard IFMA, requiring 1 h of incubation, provided a working range from 1.8 to > 900 kIU/L (CV < 10%) and a detection limit of 0.6 kIU/L. Use of overnight incubation and a lower particle concentration extended the working range by 1 decade in the lower end. Analytical recoveries for the standard IFMA varied between 97% and 108%. The slope and y-intercept of the regression line correlating measurements by the standard IFMA and a routine immunoradiometric assay were not significantly different from 1 and 0, respectively (P > 0.5), and the correlation coefficient was 0.996. High precision and warning of spuriously high measurements were obtained by including in each sample separate particle types for detecting instrument instability and measuring nonspecific binding only.
我们评估了两种基于新型大孔丙烯酸酯颗粒并结合流式细胞术的甲胎蛋白（AFP）均相免疫荧光测定法（IFMA）。标准IFMA需要1小时孵育，工作范围为1.8至>900 kIU/L（变异系数<10%），检测限为0.6 kIU/L。采用过夜孵育和较低颗粒浓度可将工作范围在低端延长1个数量级。标准IFMA的分析回收率在97%至108%之间。标准IFMA测量值与常规免疫放射测定法测量值相关的回归线斜率和y轴截距分别与1和0无显著差异（P>0.5），相关系数为0.996。通过在每个样品中包含用于检测仪器不稳定性和仅测量非特异性结合的单独颗粒类型，可获得高精度并对异常高测量值发出警告。
